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        span {
            color: red;
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<body>
<a href="http://www.baidu.cn">支付成功<span>5</span>秒钟之后跳转到首页</a>
<script>
    let htmlAnchorElement = document.querySelector('a');
    let time = 5;
    let timeInterval = setInterval(function () {
        time--;
        htmlAnchorElement.innerHTML = `支付成功<span>${time}</span>秒钟之后跳转到首页`;
        if (time === 0) {
            clearInterval(timeInterval);
            window.location.href="http://www.baidu.cn";
        }
    }, 1000)
</script>
</body>

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